Enhanced Intersection-Based Perimeter Geo-Routing in Urban Vehicular Ad-Hoc Networks

Abstract

The ongoing research in the field of vehicular communication towards cooperative Intelligent Transport Systems (ITS) tries to tackle the ever increasing road traffic problems. In urban Vehicular Ad-hoc Networks (VANET), network disconnections happen frequently as a result of fast movement of vehicles, road layout constraints, and shadowing effects caused by buildings. Therefore, one of the key factors to successfully establish VANETs, is a routing protocol, which can fulfill the Quality-of-Service (QoS) required by ITS's promised applications, e.g., traffic management, road safety and comfort. Because of the simplicity, efficiency and scalability of geo-routing protocols, they suit for VANETs. The family of greedy perimeter geo-routing protocols became a considerable solution for VANETs. Although enhancements to GPSR (Greedy Perimeter Stateless Routing) has been proposed, still there are shortcomings, which needs to be eliminated, to have geo-routing at its best. In this paper, EIPG (Enhanced Intersection-based Perimeter Geo-routing) is proposed for urban VANETs. EIPG inherits the restricted greedy forwarding of GpsrJ+ but employs a new intersection-based perimeter forwarding in order to avoid the problem of Wrong Street Estimation (WSE). Based on our profound simulation study, EIPG shows a significant improvement in comparison to GpsrJ+, in terms of Packet Delivery Ratio (PDR), end-to-end delay, and network overhead. EIPG also requires only the information of single-hops, i.e., the direct neighbor vehicles, to avoid the unnecessary overhead caused by the extra information included in the beacon messages of GpsrJ+ and be more compatible with the standard Cooperative Awareness Messages (CAM).